Improve 'pdumper-stats' and its documentation

* src/pdumper.c (Fpdumper_stats): Improve formatting and
wording of the doc string.  Decode the pdump file name and
expand-file-name it.

* doc/lispref/internals.texi (Building Emacs): Document
'pdumper-stats'.

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi
index 66606da6ecf..437657f2438 100644
--- a/doc/lispref/internals.texi
+++ b/doc/lispref/internals.texi
@@ -225,6 +225,18 @@ Emacs was built without @code{unexec} support, this function will not
 be available.
 @end defun
 
+@defun pdumper-stats
+If the current Emacs session restored its state from a portable dump
+file, this function returns information about the dump file and the
+time it took to restore the Emacs state.  The value is an alist
+@w{@code{((dumped-with-pdumper . t) (load-time . @var{time})
+(dump-file-name . @var{file}))}},
+where @var{file} is the name of the dump file, and @var{time} is the
+time in milliseconds it took to restore the state from the dump file.
+If the current session was not restored from a portable dump file, the
+value is nil.
+@end defun
+
 @node Pure Storage
 @section Pure Storage
 @cindex pure storage